#
# This file is part of SickGear.
#
# SickGear is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# SickGear is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with SickGear.  If not, see <http://www.gnu.org/licenses/>.

import os
import re

from lxml_etree import etree

from exceptions_helper import ex

import sickgear
from . import classes, helpers, logger
from .common import Quality
from .name_parser.parser import InvalidNameException, InvalidShowException, NameParser

from _23 import decode_str
from six import string_types

# noinspection PyUnreachableCode
if False:
    # noinspection PyUnresolvedReferences
    from typing import Any, AnyStr, Dict, List, Tuple

SUBJECT_FN_MATCHER = re.compile(r'"([^"]*)"')
RE_NORMAL_NAME = re.compile(r'\.\w{1,5}$')


def _platform_encode(p):
    """ Return Unicode name, if not already Unicode, decode with UTF-8 or latin1 """
    try:
        return decode_str(p)
    except (BaseException, Exception):
        return decode_str(p, sickgear.SYS_ENCODING, errors='replace').replace('?', '!')


def _name_extractor(subject):
    """ Try to extract a file name from a subject line, return `subject` if in doubt """
    result = subject
    for name in re.findall(SUBJECT_FN_MATCHER, subject):
        name = name.strip(' "')
        if name and RE_NORMAL_NAME.search(name):
            result = name
    return _platform_encode(result)


def _get_season_nzbs(name, url_data, season):
    """

    :param name: name
    :type name: AnyStr
    :param url_data: url data
    :type url_data: Any
    :param season: season
    :type season: int
    :return:
    :rtype: Tuple[Dict, AnyStr]
    """
    try:
        show_xml = etree.ElementTree(etree.XML(url_data))
    except SyntaxError:
        logger.error(f'Unable to parse the XML of {name}, not splitting it')
        return {}, ''

    filename = name.replace('.nzb', '')

    nzb_element = show_xml.getroot()

    regex = r'([\w\._\ ]+)[\._ ]S%02d[\._ ]([\w\._\-\ ]+)' % season

    scene_name_match = re.search(regex, filename, re.I)
    if scene_name_match:
        show_name, quality_section = scene_name_match.groups()
    else:
        logger.error('%s - Not a valid season pack scene name. If it\'s a valid one, log a bug.' % name)
        return {}, ''

    regex = r'(%s[\._]S%02d(?:[E0-9]+)\.[\w\._]+)' % (re.escape(show_name), season)
    regex = regex.replace(' ', '.')

    ep_files = {}
    xmlns = None

    for cur_file in list(nzb_element):
        if not isinstance(cur_file.tag, string_types):
            continue
        xmlns_match = re.match(r'[{](https?://[A-Za-z0-9_./]+/nzb)[}]file', cur_file.tag)
        if not xmlns_match:
            continue
        else:
            xmlns = xmlns_match.group(1)
        match = re.search(regex, cur_file.get("subject"), re.I)
        if not match:
            # print curFile.get("subject"), "doesn't match", regex
            continue
        cur_ep = match.group(1)
        fn = _name_extractor(cur_file.get('subject', ''))
        if cur_ep == re.sub(r'\+\d+\.par2$', '', fn, flags=re.I):
            bn, ext = os.path.splitext(fn)
            cur_ep = re.sub(r'\.(part\d+|vol\d+(\+\d+)?)$', '', bn, flags=re.I)
        bn, ext = os.path.splitext(cur_ep)
        if isinstance(ext, string_types) \
                and re.search(r'^\.(nzb|r\d{2}|rar|7z|zip|par2|vol\d+|nfo|srt|txt|bat|sh|mkv|mp4|avi|wmv)$', ext,
                              flags=re.I):
            logger.warning('Unable to split %s into episode nzb\'s' % name)
            return {}, ''
        if cur_ep not in ep_files:
            ep_files[cur_ep] = [cur_file]
        else:
            ep_files[cur_ep].append(cur_file)

    return ep_files, xmlns


def _create_nzb_string(file_elements, xmlns):
    """

    :param file_elements: first element
    :param xmlns: xmlns
    :return:
    :rtype: AnyStr
    """
    root_element = etree.Element("nzb")
    if xmlns:
        root_element.set("xmlns", xmlns)

    for curFile in file_elements:
        root_element.append(_strip_ns(curFile, xmlns))

    return etree.tostring(root_element, encoding='utf-8')


def _save_nzb(nzb_name, nzb_string):
    """

    :param nzb_name: nzb name
    :type nzb_name: AnyStr
    :param nzb_string: nzb string
    :type nzb_string: AnyStr
    """
    try:
        with open(nzb_name + '.nzb', 'w') as nzb_fh:
            nzb_fh.write(nzb_string)

    except EnvironmentError as e:
        logger.error(f'Unable to save NZB: {ex(e)}')


def _strip_ns(element, ns):
    element.tag = element.tag.replace("{" + ns + "}", "")
    for curChild in list(element):
        _strip_ns(curChild, ns)

    return element


def split_result(result):
    # type: (sickgear.classes.SearchResult) -> List[sickgear.classes.SearchResult]
    """

    :param result: search result
    """
    resp = helpers.get_url(result.url, failure_monitor=False, as_binary=True)
    if None is resp:
        logger.error(f'Unable to load url {result.url}, can\'t download season NZB')
        return []

    # parse the season ep name
    try:
        np = NameParser(False, show_obj=result.show_obj)
        parse_result = np.parse(result.name)
    except InvalidNameException:
        logger.debug(f'Unable to parse the filename {result.name} into a valid episode')
        return []
    except InvalidShowException:
        logger.debug(f'Unable to parse the filename {result.name} into a valid show')
        return []

    # bust it up
    season = parse_result.season_number if None is not parse_result.season_number else 1

    separate_nzbs, xmlns = _get_season_nzbs(result.name, resp, season)

    result_list = []

    for new_nzb in separate_nzbs:

        logger.debug(f'Split out {new_nzb} from {result.name}')

        # parse the name
        try:
            np = NameParser(False, show_obj=result.show_obj)
            parse_result = np.parse(new_nzb)
        except InvalidNameException:
            logger.debug(f'Unable to parse the filename {new_nzb} into a valid episode')
            return []
        except InvalidShowException:
            logger.debug(f'Unable to parse the filename {new_nzb} into a valid show')
            return []

        # make sure the result is sane
        if (None is not parse_result.season_number and season != parse_result.season_number) \
                or (None is parse_result.season_number and 1 != season):
            logger.warning(f'Found {new_nzb} inside {result.name} but it doesn\'t seem to belong to the same season,'
                           f' ignoring it')
            continue
        elif 0 == len(parse_result.episode_numbers):
            logger.warning(f'Found {new_nzb} inside {result.name} but it doesn\'t seem to be a valid episode NZB,'
                           f' ignoring it')
            continue

        want_ep = True
        for ep_no in parse_result.episode_numbers:
            if not result.show_obj.want_episode(season, ep_no, result.quality):
                logger.debug(f'Ignoring result {new_nzb} because we don\'t want an episode that is'
                             f' {Quality.qualityStrings[result.quality]}')
                want_ep = False
                break
        if not want_ep:
            continue

        # get all the associated episode objects
        ep_obj_list = []  # type: List[sickgear.tv.TVEpisode]
        for cur_ep in parse_result.episode_numbers:
            ep_obj_list.append(result.show_obj.get_episode(season, cur_ep))

        # make a result
        nzb_result = classes.NZBDataSearchResult(ep_obj_list)
        nzb_result.name = new_nzb
        nzb_result.provider = result.provider
        nzb_result.quality = result.quality
        nzb_result.show_obj = result.show_obj
        nzb_result.extraInfo = [_create_nzb_string(separate_nzbs[new_nzb], xmlns)]

        result_list.append(nzb_result)

    return result_list